The invention relates to an electronic data processing device, comprising an access protected memory, provided for storing secure data, in particular data related to a fund transfer, and a data processing member connected to said memory via a bus and provided for processing said secure data, said terminal comprises a tampering detection and protection circuit connected to said bus and provided for detecting a tampering condition and for generating a tampering signal, upon detection of said tampering condition, said tampering detection and protection circuit being connected to a tampering sequencer provided for disabling said processing member, upon receipt of said tampering signal.
Such an electronic data processing device is known and is for example used in an ATM (Automatic Teller Machine) or POS (Point of Sales). The access to the memory and the processing member of such a terminal needs to be carefully protected against tamper actions in order to avoid unauthorised access to the memory or the data processing member. Tamper actions can be of all kinds such as breaking open the device in order to get access to the bus or the memory. In order to detect such a tamper action, the known devices have a tampering detection and protection circuit which, upon detection of a tamper action, generates a tampering signal in order to disable the processing member, thereby avoiding that the data stored in the memory can be retrieved.
A drawback of the known electronic data processing devices is that the disabling operation needs the clock signal of the data processing member and thus to be applied synchronously with the data processing. Consequently, the processor and the bus can still be used for retrieving data before the disabling operation is finished. Since the clock signal of the data processing member is used, the latter still needs to be operational in order to erase the protected data stored in the memory.
It is an object of the present invention to realise an electronic data transfer terminal which is more efficient and provides a better tamper protection.